#include <fstream>
#include <vector>
using namespace std;

ifstream fin("asmax.in");
ofstream fout("asmax.out");

#define NMAX 16005

vector<int> G[NMAX];

int v[NMAX], viz[NMAX];

void dfs(int nod)
{
    viz[nod] = 1;

    for (auto it : G[nod])
        if (!viz[it])
        {
            dfs(it);
            if (v[it] > 0)
                v[nod] += v[it];
        }
}

int main()
{
    int n;
    fin >> n;

    for (int i = 1; i <= n; ++i)
        fin >> v[i];

    for (int i = 1; i <= n; ++i)
    {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    dfs(1);

    int maxim = v[1];

    for (int i = 2; i <= n; ++i)
        if (v[i] > maxim)
            maxim = v[i];

    fout << maxim;
    return 0;
}